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Aileron Rolls
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Aileron rolls
are flown with the rudder and elevator in the neutral
position during the roll. The aileron is fully deflected
in the direction of the roll. This is the easiest of the
rolls to fly.
The aileron
roll is started by pulling the nose up to 20 - 30 degrees
above the horizon. The elevator is then neutralized and
the aileron fully deflected in the direction of the roll.
The controls are maintained in that position till the roll
is completed. After the roll is completed the nose is
usually 20 - 30 degrees below the horizon. |
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Barrel Rolls |
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The Barrel roll is a combination between a loop and a
roll. You complete one loop while completing one roll at
the same time. The flight path during a barrel roll has
the shape of a horizontal cork screw. Imagine a big
barrel, with the airplanes wheels rolling along the inside
of the barrel in a cork screw path. During a barrel
roll, the pilot always experiences positive Gs. The
maximum is about 2.5 to 3 G. The minimum about 0.5 G.
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Slow Rolls |
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Figure 1.
(K=10) |
Figure 2.
(K=7) |
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Slow rolls
have to be flown normally on a straight line (exception is
the avalanche). The roll rate has to be constant and the
longitudinal axis of the plane has to go straight. This
requires constantly changing rudder and elevator control
inputs throughout the roll. Hesitation or point rolls
include stops at certain roll angles. The number on the
base of the roll symbol describes the number of points the
roll would have if it were a 360° roll. Allowed are 2
point, 4 point and 8 point rolls. The fraction on the
arrow of the roll symbol describes what fraction of a full
roll is to be executed. If no points are specified,
rolling is done without hesitations. If no fraction is
specified, a roll symbol that starts at the line specifies
a half roll (see description of the Immelman). A roll
symbol that crosses the line specifies a full roll (first
figure). The second figure shows the symbol for 2 points
of a 4 point roll (adding up to half a roll) from upright
to inverted flight. |
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Snap rolls also have to be
flown normally on a straight line. A snap roll is similar
to a horizontal spin. It is an autorotation with one wing
stalled. Figure 1 shows the symbol for a regular snap
roll. Figure 4 for an outside snap. In the regular snap,
the plane has to be stalled by applying positive G forces.
In an outside snap, the plane is stalled by applying
negative G. In both cases rudder is then used to start
autorotation just like in a spin. |
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Loops |
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(K=10) |
This is one of the
most basic maneuvers, but not easy to fly well. It has to
be perfectly round, entry and exit have to be at the same
altitude. The difficulty in flying this maneuver well is
in correcting for effects of wind drift.
The maneuver starts with a pull-up of about 3 - 4 G. Once
past the vertical, the back pressure on the elevator is
slowly relaxed to float
over to top of the loop to keep it round. Past the top,
the back pressure is slowly increased again throughout the
back part till horizontal flight. The plane has to stay in
one plane with the wings orthogonal to the flight path.
Rudder is used to maintain the plane of the figure and
ailerons are used to maintain the orientation of the
wings. |
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Avalanche |
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This is the basic loop with a
roll (usually a snap roll) at the top of the loop. The
roll has to be centered at the top of the loop.
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(K=21)
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Square Loop |
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This is a variation of the
basic loop. The two vertical lines and the horizontal line
on top have to be of the same length. The exit line at the
bottom has to be at least as long as the other three
sides. The quarter loops that connect the four sides have
to have the same radius at each corner. |
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(K=14)
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Eight-Sided Loop
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This is another variation of
the basic loop. The two vertical lines, the 45° lines and
the horizontal line on top all have to be of the same
length. The exit line at the bottom has to be at least as
long as the other seven sides. The eight loops that
connect the eight sides have to have the same radius at
each corner. |
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(K=19)
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Immelman
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The figure starts with a half
loop to inverted flight. A half roll then results in
horizontal upright flight. This is one of the maneuvers
that have been used in WW I to reverse direction. This
maneuver does not preserve speed and altitude. It trades
speed for altitude. |
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(K=10)
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Split-S |
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The figure
starts with a half roll to inverted followed by the second
half of a loop downward.
This is
another maneuver to reverse direction. This one, like the
Immelman, does not preserve speed and altitude. In this
case it trades altitude for speed. |
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(K=10)
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English Bunt |
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This figure also is the second
half of a loop downward, this time an outside loop. You
push forward and fly the second half of an outside loop
till you are in horizontal inverted flight. Make sure you
are not too fast going into the maneuver, otherwise you
may exceed redline speed. |
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(K=8)
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Half Cuban Eight
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Five-eighths
of a loop to a down-line at a 45° angle. The plane is
inverted at this point. Centered on this downline is a
half roll from inverted to upright. A pullout to
horizontal completes the figure.
This is
another one of the maneuvers that reverse direction. The
downline can be used to adjust the altitude and speed at
the end of the figure. |
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(K=14) |
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Cuban Eight |
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Two Half Cuban Eights can be
combined to form a Cuban Eight or Lay-down Eight. In this
figure in competition the two looping parts have to be
flown at the same altitude with the same radius. The exit
has to be at the same altitude as the entrance to the
figure. |
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(K=29)
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Reverse Half Cuban
Eight |
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This
figure starts with a pull to a 45° up-line. Centered on
this line is a half roll from upright to inverted.
Five-eighths of a loop complete the figure to horizontal
flight.
This
again is one of the maneuvers that have been used to
reverse direction while
preserving altitude and airspeed
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(K=16)
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Reverse Cuban Eight |
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Like the Cuban Eight, a
Reverse Cuban Eight can be formed by flying two Reverse
Half Cuban Eights back to back. |
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Inside-Outside Eight |
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This figure is similar to a
Full Cuban Eight, but it does not contain any rolls. The
second loop is an outside loop. Again, the two loops have
to have the same radius and have to be flown at the same
altitude. Entry and exit have to be at the same altitude.
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(K=20)
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It starts with a quarter loop
into a vertical climb. When the plane stops climbing, it
pivots around its vertical axis (which is now horizontal).
The nose moves in a vertical circle from pointing up
through the horizon to pointing down. After moving
vertically down to pick up speed again, the maneuver is
finished with the last quarter of a loop to horizontal
flight. This figure can have optionally rolls on both the
up-line and the down-line. |
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Hammerhead |
The quarter
loop is flown just like the first part of a loop. When the
plane is vertical, the elevator backpressure is released
completely. During the vertical line up, some right
aileron and right rudder is needed to maintain the
vertical attitude because of the engine torque and
p-factor. When the plane has slowed enough, full rudder
initiates the turnaround. It is followed by right-forward
stick (right aileron and forward elevator) to keep the
plane from torquing off. The pivot is stopped with
opposite rudder when the nose points straight down. When
the pivot is completed, the ailerons and rudder are
neutralized. Elevator and rudder are used to keep the nose
pointing straight down. The pivot must be completed within
one wingspan. Rolls on the downline require only aileron
input if the plane is trimmed correctly. |
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(K=17)
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This maneuver is sometimes
called a hammerhead stall. This is not an accurate name
because the airplane never stalls. The airspeed may be
very low, close to zero, but since there is no wing loading
during the turn-around, there is no stall (at zero g wing
loading, a wing does not stall). The plane is flying
throughout the maneuver with all the control surfaces
effective (although sometimes only marginally so).
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This also is one of the
maneuvers that have been used to reverse direction while
adjusting altitude and airspeed by changing the length of
the down-line. |
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Humpty-Bump |
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The figure starts with a
quarter loop to a vertical climb. A half loop then results
in a vertical down-line. The figure completes with another
quarter loop to horizontal flight. The looping part on the
top of the figure does not have to be the same radius as
the two other looping portions (the quarter loops going
into and coming out of the humpty). Again the figure can
have optionally rolls on both the up-line and the
down-line. |
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(K=13) |
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Spin |
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Spins come in 3/4, 1, 1 1/4 and 1 1/2 turns. During spin
entry, the plane has to show a stall break, followed by
the auto-rotation. The
rotation has to stop exactly after the specified number of
turns. Once the rotation has stopped, a vertical downline
has to be established.
In a crossover
spin, the plane is first stalled upright. At the stall
break, the nose is pushed forward to get into an inverted
spin while maintaining the stall. The inverted spin is
then completed as it would be for an inverted spin with
entry from inverted flight.
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(K=18) |
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Chandelle |
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The Chandelle is not used in
aerobatic competition. On the FAA power commercial pilots
test a Chandelle is defined as a maximum performance
climbing turn through 180 degrees while maintaining a
constant turn rate. The idea is that this is a "plan
ahead" maneuver. You first establish a medium bank
depending on the performance of your aircraft. Then a
smooth pull up is started. The angle of bank stays
constant during the first 90 degrees of turn, while the
pitch angle increases steadily. At the 90 degree point the
plane has the maximum pitch angle which should be close to
the critical angle of attack. During the second 90 degrees
of turn, the pitch angle is held constant, while the bank
angle is smoothly decreased to reach 0 degrees of bank at
180 degrees of turn with the airspeed close to the stall
speed. The plane should not settle during the last part of
the maneuver and the recovery. The decreasing bank angle
during the second half of the Chandelle will maintain a
constant turn rate together with the decreasing airspeed.
The turn needs to be kept coordinated by applying the
right amount of rudder. A Chandelle to the left is quite
different than one to the right because of the ever
increasing amount of p-factor in the second half of the
maneuver. |
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Wing Over |
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The Wing-Over is a competition
maneuver in glider aerobatics. You pull up and at the same
time bank the plane. When the bank increases past 45°, the
nose will start to drop while the bank keeps increasing
and the plane keeps turning. Halfway through the maneuver,
the plane has turned 90°, the fuselage is level with the
horizon and the bank is 90°. The plane is above the
original flight path. The nose then keeps dropping below
the horizon and the plane keeps turning, while the bank is
shallowed. When the bank drops below 45°, the nose is
pulled up towards the horizon and the plane reaches
horizontal flight with wings level after 180° of turn. At
the completion of the maneuver, the plane is at the same
altitude as on entry and flying in the opposite direction.
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(K=6)
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Lazy Eight |
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Like the Chandelle, the Lazy
Eight is not a competition maneuver but is required for
the power commercial pilot test. The aerobatics version of
the Lazy Eight is two wingovers back to back. The FAA
commercial pilot version is similar but the maximum bank
is only 45 degrees instead of 90 degrees. The name Lazy
Eight comes from the fact that the nose of the airplane is
following a figure 8 on its side on the horizon |
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